textproduct: Albany

SYNOPSIS

Much colder and blustery conditions expected today through tomorrow with dangerous cold in western Massachusetts and parts of Litchfield County. Temperatures finally trend milder for the end of the week with widespread rainfall likely Thursday night into Friday along with gusty winds.

SHORT TERM /THROUGH MONDAY NIGHT/

Key Messages:

- The combination of breezy winds and frigid temperatures will lead to dangerous feel-like temperatures ranging from -10F to -20F tonight into Monday morning.

Discussion:

Our parent trough will continue swinging through the Northeast today with some lingering snow showers continuing today, especially in the higher terrain areas. There was even some weak Hudson Mohawk Convergence in the Capital District that led to brief enhancement of snow showers this morning. As the main trough axis and sfc cold front push through the region this afternoon, northwest winds will turn breezy and advect an Arctic air mass into the Northeast. Temperatures today will not rise out of the 20s and as the core the cold advects eastward tonight with 850hPa isotherms dropping to -15C to -18C (or 2 to 3 std deviation below normal per the NAEFS), overnight temperatures will turn frigid. Probabilistic guidance shows greater than an 80% chance for nearly the entire region to drop under 10 degrees by Monday morning. With northwest winds remaining elevated tonight with gusts up to 15-30mph (strongest in the eastern Catskills, Taconics, Litchfield Hills and Berkshires), the combination of the cold temperatures and winds will result in dangerous wind chill or "feel-like" temperatures falling to -5F to -15F late tonight through Monday morning. Western MA and northern Litchfield County look to have the highest chance of nearing their cold weather advisory criteria (-15F and -10F, respectively) so issued the product from Midnight tonight through 9am tomorrow morning. The eastern Catskills are also close to their criteria but given that the -15F values are really for the highest terrain areas, we held off. Regardless of whether or not an area is in a cold weather advisory or not, dress warmly and in layers for your Monday morning commute and avoid prolonged exposure to the cold.

The advective cold regime continues through the day on Monday with temperatures struggling to warm through the day. In fact, outside of the mid-Hudson Valley, there is less than a 10% chance that high temperatures tomorrow will exceed 25 degrees. Given that northwest winds remain breezy through the day with gusts up to 15-25mph, the feel-like temperatures will remain chilly through the day in the single digits and teens. A weakening shortwave and some enhanced mid-level moisture will push into the region Monday afternoon resulting in morning sun fading behind increasing clouds. Overall moisture and forcing is limited so best chance for any snow showers looks to be in the southern Green where upslope can enhance forcing for ascent. Even still, only expecting coating to 0.5" of snow. Behind the shortwave, west to southwest flow quickly develops and aligns down the long fetch of Lake Ontario. This will elicit a lake effect response with a single lake band developing and becoming directed into northern Herkimer County (mainly north of Route 28) by 21 UTC Mon - 00 UTC Tues. With inversion heights remain rather high near 700hPa Monday evening, the band looks to produce moderate to heavy snow for few hours with the HREF showing 10 to 30% chance for 1" per hour snowfall rates from 00-04 UTC. By 06 - 09 UTC, moisture starts dwindling and inversion heights slowly start dropping so the band begins to weaken before falling apart by early Tuesday morning. Total snowfall amounts looks to range 2 to 5 inches but given that most accumulations will remain north of Old Forge, will likely not need a winter weather advisory. Otherwise, Monday night remains chilly in the single digits and teens albeit not quite as cold as Sunday night as the core of the Arctic air escapes to our east.

LONG TERM /TUESDAY THROUGH SATURDAY/

Key Messages:

- Temperatures trend milder middle to end of this next week.

- Increasing confidence for widespread precipitation, mainly rain, along with gusty winds late Thursday into Friday.

Discussion:

Quiet weather ensues Tuesday through Wednesday as zonal flow and sfc high pressure builds over the Northeast. A progressive yet moisture starved shortwave trough tracks across the Northeast for Wednesday into Wed night but not expecting more than some brief snow showers mainly for areas north and west of the Capital District given very lackluster moisture.

Our attention then turns to nearly full latitude trough tracking across the country for the middle to end of next week. Large scale ridging amplifies across the Northeast Wed night into Thursday ahead of it with strong southwesterly winds ushering in a much milder air mass into the region. With a 75 to 90% chance for high temperatures to exceed 40 degrees on Thursday, it will feel quite mild given the colder than normal December we have endured (Albany month to date avg temperature is -8F below normal). Beside milder temperatures, we will need to monitor gusty southerly winds as the latest probabilistic guidance shows 40 to 70% chance for wind gusts to exceed 35mph over the 24-hr period from 1AM Thurs to 1AM Fri. As the incoming trough becomes neutral to even slightly negatively tilted, strong height falls combined with impressive moisture transport will likely result in widespread rainfall Thurs night into early Friday. Given the mild air mass ahead of the trough and latest trends showing the main cold front hanging back until early Friday, p-type is likely mainly rain. Locally moderate to heavy rain rates look possible given that the strong kinematics look to direct a moisture plume out of the Gulf into the Northeast; however, flooding looks unlikely as even the 90th percentile 24 hour precipitation amounts are under 2 inches and the incoming warmth will likely not be strong enough or long-lived enough to ripen/melt the existing snow pack. Cooler temperatures and strong, gusty winds return for Friday as the main cold front marches through ushering in another Canadian air mass. Will need to monitor northwest wind gusts on Friday as latest probabilistic guidance shows 40 to 70% chance for 40mph or higher gusts from 1AM Fri to 1AM Sat.

AVIATION /19Z SUNDAY THROUGH FRIDAY/

Through 12z/Mon...Wave of low pressure will continue to bring periods of snow until around 14z/Sun at KPOU/KPSF with IFR/MVFR conditions before tapering off. Any snow showers/flurries have tapered off at KALB/KGFL. Cigs through this morning will be in the MVFR/VFR range though some brief IFR cigs could occur at KPOU before the snow ends. This system will depart the TAF sites later this morning with cigs lifting back to VFR though remaining MVFR at KPSF due to upslope flow. A few additional snow showers may develop between 18z/Sun and 00z/Mon upon the passage of an upper level shortwave so maintained PROB30 groups with this update. Clouds begin to decrease in coverage after 00z/Mon but remain MVFR for a while at KPSF due to upslope flow.

Wind will become north to northwesterly this morning and remain in these directions through the TAF period. Sustained winds increase to 10-15 kt with gusts of 20-25 kt.

Outlook...

Monday Night: Low Operational Impact. Slight Chance of SHSN. Tuesday: No Operational Impact. NO SIG WX. Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: No Operational Impact. NO SIG WX. Wednesday Night: No Operational Impact. NO SIG WX. Thursday: Low Operational Impact. Breezy. Slight Chance of RA. Thursday Night: High Operational Impact. Breezy. Definite RA. Friday: Moderate Operational Impact. Windy With Gusts To 35 kts. Chance of RA...SN.

ALY WATCHES/WARNINGS/ADVISORIES

CT...Cold Weather Advisory from midnight tonight to 9 AM EST Monday for CTZ001. NY...None. MA...Cold Weather Advisory from midnight tonight to 9 AM EST Monday for MAZ001-025. VT...None.